Functional group-terminated polymers such as polymers having hydroxyl groups or the like introduced to both ends of the molecule are useful as materials for polyurethane, adhesives, modifiers, coating compositions, sealing agents, etc.
Isobutylene-type unsaturated group-terminated polymers are known as such functional group-terminated polymers.
For example, a process for preparing an isobutylene-type functional group-terminated polymer is reported (specification of U.S. Pat. No. 4,524,188) in which a Cl-terminated polymer is prepared by the Inifer method (specification of U.S. Pat. No. 4,276,394) comprising cationically polymerizing isobutylene in the presence of 1,4-bis(.alpha.-chloroisopropyl)-benzene (hereinafter referred to as "p-DCC") serving as an initiator and concurrently as a chain transfer agent, and BCl.sub.3 serving as a catalyst, and the obtained polymer is subjected to reaction for removal of HCl from the polymer.
However, the reported method involves numerous reaction steps, and therefore is not convenient.
A simplified method for introducing unsaturated groups to an isobutylene-type Cl-terminated polymer is known in which the isobutylene-type polymer with Cl groups at both ends obtained by the Inifer method is reacted with allyltrimethylsilane in the presence of a Lewis acid to thereby convert into a polymer having allyl groups at both ends (Japanese Unexamined Patent Publication No. 105005/1988).
Our research revealed, however, that the process disclosed in Japanese Unexamined Patent Publication No. 105005/1988 has problems. For example, unsaturated groups are introduced to ends of the molecule in a low ratio, and it is necessary to use an expensive material.